HC Deb 16 April 1969 vol 781 cc269-70W
Mr. Hay

asked the Postmaster-General how many houses in the area of the Washington New Town experiment are now connected to the Post Office television relay system.

Mr. Stonehouse

None.

Mr. Hay

asked the Postmaster-General what is the approximate length of television relay cable laid by or on behalf of his Department in the area of the Washington New Town experiment to the latest convenient date.

Mr. Stonehouse

To date, about 400 yards.

Mr. Hay

asked the Postmaster-General what is the approximate length of telephone cable laid in the area of the Washington New Town experiment by or on behalf of his Department to the latest convenient date.

Mr. Stonehouse

None so far.

Mr. Hay

asked the Postmaster-General whether, in the area of the Washington New Town experiment, the television relay cable and the telephone cable are contained in a combined cable or are physically separate.

Mr. Stonehouse

Physically separate.

Mr. Hay

asked the Postmaster-General when the television relay head-end equipment for Washington New Town will be installed.

Mr. Stonehouse

It is hoped to start installation this week.

Mr. Hay

asked the Postmaster-General how many subscribers to the Post Office system of combined television and telephone service in Washington New Town are now on service; and how many will be on service by June, 1969.

Mr. Stonehouse

None. The relay service will commence when the first houses to be served are occupied, probably in June this year. The number will depend on the rate of completion of the houses and the speed at which tenants move in.

Mr. Hay

asked the Postmaster-General what types of equipment and cable he is providing for the Washington New Town experiment; and in what respects they differ from the orthodox very high frequency communal aerial equipment and cable in use in Great Britain and abroad for many years.

Mr. Stonehouse

The coaxial cable to be used has been maufactured to Post Office specification; on the main highways it has a solid polythene dialectric and an outer conductor in the form of seam welded copper tube of 0.345 in. diameter. Its characteristic impedance is 75 ohms, and the attenuation per mile is 110 dB at 230 MHz. Line repeaters, specially protected for underground mounting and having a gain of 23dB, will be provided at intervals of about 0.2 mile. A more flexible cable will be used in the distribution highways. The characteristic impedance is 75 ohms, and at 230 MHz attenuation is about 120 dB per mile. Automatic alarm facilities and reliable power supplies should contribute to a high standard of performance. The system being installed does not in principle differ from orthodox VHF relay distribution systems. Its significance lies in that it has been planned to be adaptable to provide the basis for an integrated network capable in the future of offering many additional facilities.